During your senior year you will be contacted by an HRC officer who will ask for some information about what you will be doing after graduation (BOLC, residency, snow-birding, or starting to work right away). Having completed BOLC already you will be a top priority for HRC to cut your orders, but even still don't worry if you don't have them in hand until a few weeks before graduation (it's incredibly stressful, but completely out of your hands). Luckily, HRC can be very flexible/accommodating so you can ask for a specific report date and most likely you will get what you ask for - take a couple months off if you need a vacation, or start working right away if you want to get paid and start chipping away at your ADSO.
I completed BOLC before school as well and I took 2 weeks between graduating and reporting (you could technically request just 1 week if you wanted, but I would recommend taking at least 2 so that your move can be a bit easier). Here is the kicker though: coming straight from school to your duty station, you most likely will have picked out a place to live so your DENTAC HQ may not give you any permissive TDY when you sign into post (standard is a week or so of essentially free leave to get your housing sorted). You could always have your stuff packed up at school and shipped into storage at your new duty station and go house hunting when you sign into post to get that free permissive TDY, but that extra stress didn't really make the permissive TDY worth it to me (I wrongly assumed I would just be given some free time off to get settled but since I got housing myself a couple days before reporting that was denied).
Here was my timeline just to give you an idea: graduate Sunday 22MAY, movers come and pick up my stuff the following Thursday 26MAY, I start my two-day drive to my duty station 31MAY and arrive to move in 1JUN, my stuff is delivered Saturday 4JUN, and I report to post Monday 6JUN to sign in and start getting paid as an active duty CPT. It takes about a week to inprocess the installation and a couple weeks to onboard the DENTAC (get credentialed, get privileges, and start working). Make sure you are in a position to get your dental license immediately after graduation - you cannot sign your 63A contract as a general dentist without it and don't get paid your $20k bonus split over the year until you initiate the credentialing process which requires that license - for me that meant getting paid as an active duty CPT starting 6JUN and signing my contract around 14JUN to start receiving the dental bonus (I had everything ready to go the day I signed into post so I really can't see being able to sign your contract any sooner than that).
Best of luck starting your career - remember that things will go slow unless your are proactive and push to get things done yourself, be nice to everyone you deal with but getting from dental school to active duty requires that you take an active role in the process.